A common problem in the orthopaedic industry is the need for accurate bone resection prior to implantation of a prosthesis, particularly of prosthetic joints. Appropriate positioning of the prosthesis has been shown in many cases to be a leading factor in long term stability of such prosthetic joints. This is true with respect to all types of prosthetic joints. The industry, however, has relatively neglected the ulna at the elbow joint.
A current standard of practice is to perform bone resection by hand without guidance of any kind, regardless of implant type. With respect to total elbow arthroplasty (TEA), loosening of the ulnar stem of the elbow prosthesis is a commonly reported complication. This complication raises questions related to surgical technique and its relationship to the complication.
As indicated, little work has been done specifically for the ulna in the area of designing precision surgical techniques for resection of the ulna bone and implant (prosthesis) positioning. A current and primary benchmark for arthroplasty for the past twenty years has been the Coonrad-Morrey prosthesis from Zimmer of Warsaw, Ind. The Coonrad-Morrey system, however, provides very little in terms of instrumentation for determining and positioning the implant relative to existing anatomy of a patient. One device for assistance in resection of the ulna for a TEA is the Solar Elbow™ from Stryker Howmedica Osteonics of Kalamazoo, Mich. The Solar Elbow™ provides with its instrumentation a device designed to assist in resection of the ulna to a shape complementing the implant. The Solar Elbow™ provides a template shaped to complement the implant that is held up to the bone and which is used to cut along. One problem with the Solar Elbow™ resection device is that there are no ties or reference to existing anatomy.
In U.S. Pat. No. 4,624,250 issued on Nov. 25, 1986 and U.S. Pat. No. 4,718,414 issued on Jan. 12, 1988 to Saunders et al., there is disclosed an instrument for elbow surface replacement arthroplasty (the “Saunders instrument”). The Saunders instrument and method of use bases resection of an ulna for elbow arthroplasty on the patient's humeral anatomy, particularly the condyles of the humerus. Particularly, Saunders uses the condyles of the humerus to establish a center of rotation for the humerus and relates such back to the ulna for resection thereof. Several problems, however, exist with the Saunders instrument and method of use. One problem is that there is no method for accounting for soft tissue balance. Resection is made from the anatomical center of the humerus with little consideration of the ulna. Another problem is that many cases exist in elbow arthroplasty in which the condyles of the humerus have been fractured or otherwise rendered useless, and thus cannot be used as a reference.
What is thus needed is a bone resection guide and/or method of use that utilizes the ulna as a reference for resection of the ulna.
What is thus further needed is a bone resection guide and/or method of use that allows resection of an ulna in a manner that allows precise placement of a final prosthesis or implant.